Which of the following statement(s) is (are) true about respiration?

(i) During inhalation, ribs move inward and diaphragm is raised

(ii) In the alveoli, exchange of gases takes place i.e., oxygen from alveolar air diffuses into blood and carbon dioxide from blood into alveolar air

(iii) Haemoglobin has greater affinity for carbon dioxide than oxygen

(iv) Alveoli increase surface area for exchange of gases

(A) (i) and (iv) 

(B) (ii) and (iii)

(C) (i) and (iii) 

(D) (ii) and (iv)

 

Answer.:

Let’s go through the options:

(i) During inhalation, the volume of lungs increases . So, the ribs move outwards and the diaphragm is lowered .

Inhalation and Exhalation of air in lungs-01.jpg

(ii)  Alveoli are bag-like structures present in the lungs. 

They help in the exchange of gases by increasing the surface area. 

Oxygen from alveolar air diffuses into blood and carbon dioxide from blood is diffused into alveolar air.

Exchange of gases at alveoli-01.jpg

(iii) Haemoglobin has more affinity for oxygen than for carbon dioxide.

Haemoglobin carries oxygen in blood-01.jpg

(iv) Alveoli increase surface area for exchange of gases



So, the correct option is (d) (ii) and (iv)

  1. Class 10
  2. Chapter 6 Class 10 - Life Processes (Term 1)

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CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo